This invention relates to methods and apparatus for supplying headed fasteners such as bolts or rivets to a fastening machine, and more particularly to a mechanism wherein headed fasteners are released one at a time and are supplied to an automatic fastening machine in a predetermined orientation.
Automatic fastening machines, i.e., machines that automatically insert fasteners into a part for assembly purposes, are used in a variety of industrial applications. For example, in the aircraft industry machines that automatically drill a hole and install a fastener are used in fabricating wing spar subassemblies and other portions of the aircraft.
Some automatic fastening machines require large capacity fastener feed systems to ensure that an adequate supply of fasteners are available for use in the fastening machine. The large capacity feed systems currently in use are often expensive, and are of such a large size and weight that it is often necessary to mount the feed system remotely from the fastening machine. One type of such large capacity feed systems utilizes vibratory bowl-type feeders such as is disclosed in U.S. Letters Pat. No. 2,918,163 to Willis.
While large capacity fastener feed systems perform adequately in the intended environment, other automatic fastening machines require fewer fasteners and are adequately serviced by a limited capacity fastener feed system. The drawbacks of using a large capacity feed system on an automatic fastening machine requiring a more limited number of fasteners include the excessive cost involved and the excessive use of space to mount the feed system. Another drawback of a large capacity feed system using a vibratory bowl-type feeder in such an application is that the feeder must be supplied with electricity or another type of power.
An additional consideration in the design of both large and limited capacity fastener feed systems is that automatic fastening machines that use headed fasteners, e.g., bolts or head-type rivets often require that the fasteners be supplied in a particular orientation. Even further, it is usually desirable that a fastener feed system for headed fasteners be configured for handling fasteners of various shank or grip lengths.
Accordingly, it is an object of this invention to provide a fastener feed system for use on an automatic fastening machine that is relatively inexpensive to manufacture, install and operate. Another object of this invention is to provide a fastener feed system of limited size and weight that can be mounted directly on or in close proximity to an automatic fastening machine. It is a further object of this invention to provide a fastener feed system that is capable of handling headed fasteners of different grip lengths and that will deliver such fasteners to the fastening machine in a particular orientation.